World Tracker turns anyone into a cellphone spy

Forget those piddly
wiretaps. The next frontier in warrant-free surveillance is upon us, and it's open to everyone. A UK service called
World Tracker apparently uses cell tower data (or GPS, when available) to track the location of just about any GSM
cellphone. Just enter the number you want to track into the service's handy Google Maps-based interface, and you'll be
able to zoom in on the device's location, with accuracy somewhere between 50 and 500 meters. The first time you try to
track a phone, a text message is sent to the owner, who must reply in order to enable tracking (we'll leave it to you
to figure out how to work around this if you need to track a spouse, kid or employee). The service is currently
compatible with O2, Vodafone, Orange and T-Mobile in the UK, and has plans to expand to other markets including
Germany, Spain, Norway and the US. If, that is, privacy advocates don't shut it down first.